Heavy motor-tractor



R. BERNAT.

HEAVY MOTOR TRACTOR.

APPLICATION FILED APR. 3, 1918.

Patented July 20, 1920.

2 SHEETS-SHEET l.

lNvENToR'- RAOUL BERNAT ATToRNEK.

RpB'ERNAT.

HEAVY MOTOR TRACTOR. APPLICATION FILED APR. 3, 1918.

Patented July 20, 1920.

2 SHEETS-SHEET 2.

INvENT'on: RAOUL BERNAT BY-"/VMLOAL/lww( lof RAOUL BERNAT, 0F BORDEAUX, FRANCE.

HEAVY MOTOR-TRACTOR. l

Application filed April 3, 1918.

To all whom 'it may concern:

, Be it known that I, RAoUL BERNAT, a citizen of hepublic of France, and residing at Bordeaum Gironde, 6 Fue des Douves, have invented new and useful improvements in lileavy Motor-Tractors, of which the following is a specification.

This invention has for its object to provide a heavy tractor of high power, intended or traveling slowly, and adapted to travel over surfaces of almost'any kind, even soft or irregular surfaces. Such a tractor should be capable, for example, of being used for the drawing or propulsion of heavily loaded vehicles including artillery wagons and the Y.

like, which may have to travel over bad road surfaces or even over fields. Such la tractor should also be capable of heiligy used for drawing agricultural implements such as plows. f

The tractor forming the subject of the present invention fuli'ils these requirements and comprises'in combination with a suitable motor, preferably an internal combustion engine, a system of limbs or crutches suitably jointed and having imparted to them alternating backward Vand forward movements which they transmit to shoes suitably formed for engaging with or ground surface in one direction-of movement or the other; these limbs `nd shoes may be thrown out of action whenever desired.'

' The invention is illustrated by way of eX- ample in the accompanying drawings, where-v in Figure l is a diagrammatic elevation and F 2 a diagrammatic plan view of a tractor constructed according to the invention.

Figs. 3 and 4- represent the same views of a modication of the said tractor.

The tractor comprises in either case a chas-l sis a similar to those of motor cars or wagons, and carrying an internal combustion engine 6 which is preferably placed at lthe front. :The chassis runson four wheels, the front wheels l being steeringl wheels of a usualtype, while the rear-wheels 2 are suppor ing and running wheels, (Figs. l and 2), but the arrangement, as shown in-Figs.

3 and 4, is a different one, as will be stated hereafter.

TheV engine 6 drives through suitable gearing including a worm drive e, a countershaft Z on which are keyed, for example, a number of eccentrics or cranks rforming two sets e and f. The eccentrics ofthe set e operate the Specification of Letters Patent.

shoes are provided in each ratentedauiy 2o, 19.20. serial No. 226,542.

limbs g directed rearwardly of the vehicle, while the eccentrics of the set 7 operate the forwardly directed limb or limbs 7L.

The limbs are jointed at 3 sov as to allow them to turn laterally, and they carry at their ends shoes z' provided with ribs or teeth on their under surface, these shoes being made as long as is conveniently possible, and jointed to the limbs at l so as to allow of a hinging movement relative thereto.

` The eccentrics of each set are keyed at angles of 180, 1200 or 900 apart, according as two, three or four eccentrics, limbs and set. wheel or winch j operating chains 7c, is renders it possible to lift either the limbs f/ or the limbs L into a position such that the one set of shoes may be thrown out of action completely before the other set comes into contact with the ground; the lifting of the limbs may be effected to any required extent during ltheir working. In the example shown the vchain 7u is connected directly to the front limb 7L while the chain 7c transmits its lifting movement to the rear limbs through a lever Z and arms m connected to the limbs by vchains* c.

The rear lifting chain may be attached either to the bell crank lever Z, as shown in ig. l, or as'represented by Figs. 3 and l, to a crank lever Z, that is to say either on the link or limb g, between the eccentric and shoe, or Vupon a suitable extension r of the said limb, behind the articulation point or joint with the shoe.

The lifting winch j maybe replaced by a llever working over a notched segment, or

'anyother lifting and lowering mechanism wholly or parder the engagement of the shoes z' with the ground more or less effective as required. The duration of contact of each shoe z `with the ground is reduced 1n proportion to the CIK ' clutch being in `gear with Vnatively lowering height to which the shoe is raised, and the speed of forward movement of the tractor is reduced in proportion. This result is obtained by hinging the limbs from the chains 7c, 1 which causes the shoes to take a curved path of movement when suspended freely.

The joints 3 of the limbs make it possible for the vehicle to turn laterally, inasmuch as the limbs are free to swing to one side or the other, and during this operation it is Apreferable to reduce the propelling' speed of trated is preferred as being the simplest and least'expensive in practice.

In order to takefa curve'cf areduced radius, the means represented as-a modi.-` lication in Figs. 3 and 4 maybe advantageously used.' Y v Y -V To this end, the free running wheels a may be made as driving wheels, by provid ing them with crown orrsprocket wheels 0 in connection by means of chains g with two other sprocket wheels p which loosely turn upon opposite ends of :the shaft Z and maybe eitheruthrown into or out of gear by means of suitable clutches t mounted on shaft Z and controlledv by levers or equiva-V lent devices fr.

'With such a device, as the lea-dinger guide wheels are vturned in the proper direction, the curve will be taken either to the right or to the left, depending upon the Y the one or the other of the wheels y). Having thus described my invention what I claimv as new and desire to secure by Letters Patent is: l Y

V1. In a high power tractor, the/*cmbination of a chassis having f-ront and rear wheels; a motor two sets of pushing crutches embodying limbs pivotally mountedat their upper-ends forlateral swinging movement and shoes pivotz'illy connected to the lower Vends of said limbsfor vertical swinging movement, onev set of crutches for propelling the tractor' forwardly-and the otlierset 'iorpropelling it rearwardly; mechanism for alterorfraising either set of crutches toward or from the groundv Vto throw it -intoor' out of action and `to control the duration 'of engagement of the shoes with the ground and, consequently, the direction andspeed of the tractor; operating vtion of a chassis having front mounted on the chassis;`

connections between the motor and the crutch sets; driving connections between the motor and the rear wheels; and clutch mechanism operable to throw either driving connection into action to enable the tractor to be turned iii-either direction.

2. In a high power tractor, the combination of a Ychassis having front and rear wheels, a motor mounted on the chassis; two sets of pushing crutches embodying limbs pivotally mounted at their upper ends for lateral swinging movement and shoes pivotally connected to the lower ends of said limbs for vertical swinging movement, one set of crutches for propellingthe tractor forwardly and the other set forpropelling it rearwardly; mechanism for alternately lowering either set of crutches/toward the ground to" throw it into actionand simultaneously raising the other set above the ground to throwit'out of action, and for .controlling the period of engagement of the shoes of the activesetwith the ground and, consequently, the direction and speed of the tractor; and operating connections between the motor and the crutch sets.`

3. VIn a high power tractor, the combinaand rear wheels, a motor mounted on the chassis; two sets of pushing crutches embodying limbs pivotally mounted at their upper ends for lateral swinging movement Vand shoes pivotally connected' to the lower ends of saidl limbs for vertical swinging movement, one set of crutches for propelling the tractor forwardly and theother set for propellingit rearwardly; a winch mounted on the chassis and having operating means connected to it; flexiblel means carried by the winch and connected at one end with one set of crutches and at the opposite end with the other set for alternatively lowering Veither set toward the ground to throw it into actionand simultaneously raising the other set above the ground to throw it out of action, and for controlling vthe period of engagement of the shoes of the active set with the ground and, consequently, the direction and speed of the tractor; a deviceinterposed between one of therends vof the flexible element and the adjacent set'of crutches consisting of a crank lever to which said end is directly attached, arms connected to move with' said lever, and chains connected at opposite ends' to 'said arms andiset of crutches; and operating connections between the motor and the crutch sets;` `l 'Y In4 testimony whereof I have signed my name to thisspecilication in the presence of two subscribing witnesses.

. i .RAOUL BERNATi VfVVitnesses: f

E. J. BOURGOIN,` JEAN ABADIE.. 

